Mechanic’s Lien Rights FAQ for Construction Teams

Mechanic's liens might be one of the most powerful payment tools available to general contractors (GCs), subcontractors, and suppliers, but they’re also one of the most misunderstood. And with good reason: rules for mechanic’s liens vary by state, role, and project type. 

This confusion is why we hosted our webinar, For the Love of Liens: Protecting Your Payments from Start to Finish, and judging from the flood of questions we received from the hundreds of contractors in attendance, no one is alone in their frustration and bewilderment.

We compiled the most broadly useful mechanic’s lien questions here. And since a fair number that came through were state-specific, we’ve linked to our 51-state lien rights directory (including D.C.). It’s the best place to get the latest lien law details for wherever your projects are based.

Keep in mind that everything here is for general informational purposes only. We're not lawyers, and this is not legal advice. For anything specific to your situation, consult a qualified construction attorney.

Who Can File and What Qualifies

What is a mechanic’s lien, and how does it work?

A mechanic's lien is a legal claim that attaches to a property when a contractor, subcontractor, supplier, or laborer isn't paid for work they performed or materials they furnished. Once recorded, it prevents the property owner from selling, refinancing, or transferring the property until the debt is resolved. 

Unlike a mortgage, a lien doesn't require the owner's consent. It's one of the most powerful collection tools available in construction—and often, the threat of filing is enough to prompt payment.

Who can file a mechanic's lien?

Broadly speaking, anyone who contributes to the permanent improvement of a private construction project may have lien rights. That often includes:

• General contractors
• Subcontractors at any tier
• Material suppliers
• Laborers
• Equipment rental companies (in most states)
• Design professionals like architects and engineers, when their work is tied to the construction

The specific rules vary by state and by where you land in the project hierarchy (GC, sub, sub-sub, supplier, etc.).

Can suppliers file mechanic's liens?

Yes, in most states, material suppliers have lien rights for materials they furnish to a project, so long as those materials are actually incorporated into the property. Keep in mind that preliminary notice requirements often apply to suppliers, just like they do to subcontractors. 

Check your state's laws to understand what's required of you. If you supply materials and provide installation, you can typically cover both under a single lien.

What work actually qualifies for a mechanic's lien?

Lien rights generally apply to work that permanently alters, enhances, or adds value to a property. That typically includes on-site labor, materials incorporated into the project, and equipment used on the job. It usually does not include office overhead, unused materials, or warranty work performed after project completion. 

When in doubt, stick to what was actually furnished on-site and documented.

Can I file a mechanic's lien against a public entity, such as a school district or a government building?

No. You can only file mechanic's liens on private property. You cannot place a lien on government-owned property (local, state, or federal).

For public projects, your primary payment protection comes through a different mechanism: a bond claim. On state and local public projects, this is typically covered by a "Little Miller Act" bond (named after the federal Miller Act, which governs federal public projects). The contractor is required to post a payment bond, and you file a claim against that bond rather than the property itself.

The requirements for bond claims—including notice deadlines and filing procedures—also vary by state.

Preliminary Notices and Notices of Intent

What is a preliminary notice, and why does it matter?

A preliminary notice is a formal notice sent to the property owner—and often the GC and lender—informing them that you're working on a project and may have lien rights if not paid. It's not a request for money; it's a protective step that preserves your ability to file a lien later if things go wrong.

In 27 states, preliminary notices are required for commercial subcontractors to maintain lien rights. Miss the deadline, and your lien rights may be gone entirely. Even in states where it's not required, sending one is a smart practice as it signals to the owner and GC that you're running a professional operation and are serious about getting paid.

What’s the difference between a preliminary notice and a Notice of Intent (NOI) to Lien?

A preliminary notice is an early-project notice. It’s typically sent shortly after you first furnish labor or materials, and its purpose is to preserve your right to file a lien later if you’re not paid. It’s not a threat, but rather a compliance step.

A Notice of Intent (NOI) to Lien, on the other hand, is a warning you send before you actually file a lien. It essentially tells the owner that if this bill isn’t paid, you’ll file a lien on the property. More often than not, this gets their attention because a recorded lien can disrupt draws, delay refinancing, and hold up a sale or project closeout. For that reason, many owners and GCs pay up once they receive an NOI.

If your state requires an NOI and you skip it, your lien could be invalid even if everything else was done correctly.

When is the deadline to file a preliminary notice?

The deadline varies by state and is usually tied to when you first furnished labor or materials to the project, rather than the contract execution date or the overall project start. Some states require the notice before you begin work; others allow a window after first furnishing. Deadlines commonly range from 20 to 60 days after first furnishing. Check the lien rights directory for your state for the specific timeline.

What date triggers the preliminary notice deadline?

Most states tie the deadline to the date you first furnish labor or materials, i.e., when you actually show up and begin work or deliver materials. If you're a sub that doesn't start until several weeks into a project, your clock typically starts when you first furnish, not when the project breaks ground. Confirm the language for your state in our mechanic’s lien guides.

Does a preliminary notice need to be filed with the county recorder's office, or is notice by certified mail sufficient?

It depends on the state. Some states require filing with a state or county registry (Utah's State Construction Registry is one example), while others simply require delivery to specified parties via certified mail. Using the wrong method can invalidate the notice even if the content is correct, so check your state's requirements and always retain proof of delivery.

If my contract value changes, do I need to resend a preliminary notice?

Generally, no. Preliminary notices cover the labor and materials you furnish to the project, not a fixed contract amount. Even if your scope grows, you typically don't need to re-serve the notice just because the dollar value increased. If you expand into a separate phase or a new project on the same property, a supplemental notice is a good idea.

Is there a problem with overstating amounts on a lien?

Yes, and it’s one of the fastest ways to lose an otherwise valid lien.

Any lien you file must closely match the actual unpaid amount for lienable work. Overstating a lien can get it challenged, reduced, or thrown out entirely in many jurisdictions. And in some states (for example, California, Colorado, Florida, New York, and Texas), knowingly exaggerating a claim can expose you to penalties, attorney’s fees, or even liability for damages.

So calculate your lien amounts carefully. Stick to documented, unpaid labor and materials that are actually lienable under your state’s law. And because what’s “lienable” varies by state, it’s worth reviewing your state’s specific rules before recording the claim.

Filing a Mechanic’s Lien

Can I file a mechanic's lien during an active project, or only once the job is finished?

You can file a lien at any point when you have unpaid work. So, if you're not being paid on progress bills, you have the right to file a lien for the unpaid amounts while work is still ongoing. You'll lien for the amount you haven't been paid, not your total contract value. Just make sure your documentation is tight, and you're not filing for more than you can legally claim.

What's the difference between "date of last furnishing" and "date of completion"?

These are two separate concepts that can affect your lien deadline.

1. Date of last furnishing is the last day you provided labor, materials, or services to the project. Your lien filing deadline is usually calculated from this date, so it's personal to you—not the project as a whole.
2. Date of completion (or "after completion") refers to the overall completion of the project, which may be triggered by events like filing a notice of completion or ceasing work on the project. Some states tie certain deadlines—particularly for lien claimants who didn't send a preliminary notice—to the project completion date rather than the individual's last furnishing date.

The distinction matters a lot: if you're working off the wrong date, you may assume you have more time than you actually do. 

For the Oregon-based masonry contractor who asked about this during the webinar: in Oregon, the 75-day window to record a lien runs from your date of last furnishing—and four hours of punch work by a foreman with an accepted final CPR can count, but this is exactly the kind of situation where a construction attorney's input is valuable.

What information does a mechanic's lien need to include?

At a minimum, most states require:

• The lien amount
• Your business information
• The owner or hiring party's information
• A description of the property (in some states like Michigan, this must be a full legal description, not just a street address)

Some states have a statutory form you're required to use. Others require only that specific information be included in whatever format you choose. Missing or incorrect information is one of the most common ways to invalidate a lien, so slow down and double-check everything before you file.

What happens after I file the lien?

Filing is not the last step. In many states, you're also required to serve a copy of the filed lien on the property owner—and sometimes the GC or lender—within a specific window and via an approved delivery method (usually certified mail or a licensed process server; dropping it off yourself typically doesn't count). Missing the service step can invalidate the lien even if it was filed correctly and on time.

After filing, if the payment still doesn't come, you have a limited window to enforce the lien by filing a foreclosure lawsuit. That enforcement deadline varies widely by state—as short as 90 days in Massachusetts and as long as six years in Ohio. Once the enforcement window closes, the lien expires.

When you finally do get paid, many states require you to formally release the lien from the property. Failing to release after payment can expose you to penalties or legal claims.

How do I find out who the lender is on a project?

Check the county property records for the location where the project is based. If there's financing in place, there will typically be a recorded deed of trust or mortgage that lists the lender. You can also check the building permit application (the lender is sometimes listed there) or simply ask the GC directly if your relationship allows for it.

Lien Rights and Your Contract

Which state's lien laws should I refer to: the state the project is physically in, or the state where the GC is headquartered?

In almost all cases, lien rights are governed by the state where the project is physically located. Lien rights attach to the real property, and that property exists in a specific state.

However—and this is important—some GC contracts include language stating that the contract is governed by the laws of the GC's home state, or that disputes will be resolved under a different jurisdiction. This language can affect your contractual remedies and dispute resolution options, even if lien rights technically still follow the property's state. Read your contract carefully. If you see unusual governing law language, consult your attorney.

Can a GC contract say I'm not allowed to file a mechanic's lien?

In the vast majority of states, no, you cannot waive lien rights in advance through a contract clause. Courts in most states treat mechanic's lien rights as a statutory protection that can't be bargained away before the work is done.

If you see language in a GC contract saying you waive your lien rights or won't file a lien, push back. In most states, that clause won't hold up anyway, but you don't want to sign something that could create confusion or be used against you later.

What is a stop notice, and how is it different from a mechanic's lien?

A stop notice is a separate legal remedy available in some states (most notably California) that allows an unpaid contractor or supplier to demand that a construction lender hold back funds from the borrower until the debt is resolved. Unlike a lien, which attaches to the property itself, a stop notice targets the loan funds directly.

In California, a stop notice can be filed on both private and public works projects, making it a useful tool when a mechanic's lien isn't available (i.e., on public projects). It can also be used alongside a mechanic's lien on private projects for additional leverage. Requirements and procedures are distinct from the lien process, so check California's specific rules if you're working there.

Lien Waivers and Lien Rights

What should I do if a GC asks me to sign an unconditional waiver before I've actually been paid?

Don't sign it. Once you sign an unconditional waiver, you've released your lien rights for that amount—even if the check never arrives, bounces, or gets delayed. It's binding from the moment you sign.

Some GCs will hold the waiver in escrow and only process it once payment is released; that's a more acceptable arrangement. But if a GC is simply asking you to sign the unconditional upfront with nothing in return, hold your ground and offer a conditional waiver instead. If they push back, you have every right to explain why. 

For more on handling waiver timing and pressure tactics, check out our lien waiver FAQ. And for state-specific lien waiver questions, we have an entirely separate directory dedicated to that. 

I want to add language to an unconditional waiver to exclude retainage or other unpaid amounts. Is that OK?

This is understandable, but proceed with caution. In states with statutory waiver forms (like Arizona, California, Michigan, and Texas), deviating from the required language can invalidate the waiver entirely. 

In most cases, a better approach is to use the waiver's exceptions section. Many waiver forms include a specific field for listing amounts not being waived (e.g., retainage, unapproved change orders, etc.). That keeps the document intact while protecting your rights on the excluded amounts. 

If you're in a state without a statutory form and you do decide to add protective language, it’s still worth discussing with the GC before submitting a modified document, as surprises on waivers can delay payment.

Change Orders and Lien Rights

How do unapproved change orders affect my lien rights?

Unapproved change orders are one of the biggest risks to a clean closeout. If you've performed work that hasn't yet been approved or added to the schedule of values, it can look like you've been paid in full when you actually haven't. That's especially dangerous at final closeout, when signing an unconditional final waiver would release your rights on everything, including any work you haven't yet been paid for.

Keep unapproved change orders listed as exceptions on your lien waivers until they're fully approved, billed, and paid. And if you haven't been paid for that work, it can be included in a lien claim as long as you have documentation proving the work was performed.

Can I file a lien for unapproved change orders?

Yes, in most states, you can include unapproved or disputed change orders in a lien if you can document that the work was actually performed. The key is thorough documentation, e.g., change order requests, project communications, site logs—anything that demonstrates the work was performed but not compensated. 

Keep in mind that contract requirements (like written approval provisions) can affect enforceability, and overstating your claim can put the entire lien at risk. Only lien for work you can clearly substantiate.

Does my contract affect how I handle change orders based on my lien rights?

Yes. Some contracts require you to notify the GC or owner of a cost impact within a specific window (sometimes as short as 7 days) before you can even submit a formal change order. If you miss that contractual notice requirement, you may lose your right to be compensated for that work, which in turn affects the amount you can lien. Read your contract for change order notification clauses and make sure your PMs know the deadlines.

Special Situations

Can engineers, architects, or other design professionals file mechanic's liens?

Yes, in most states. Design professionals whose work is tied to the construction—such as engineers who prepare plans that are actually used on a project—can file mechanic's liens in most jurisdictions. That said, the rules often differ from those that apply to subcontractors, including when lien rights attach and what notice requirements apply. Check the lien rights directory to understand how design professionals are treated under your state's law.

We currently supply materials, but are also expanding to offer installation. Will we need to file separate liens?

Generally, no. You can cover both supply and labor under a single lien for a given project. Once you're furnishing both materials and labor on a job, you can capture all that work on one claim. Keep in mind that adding labor to your scope may also change your preliminary notice requirements or other lien procedures (e.g., moving from a "materials supplier" category to a "subcontractor" category in some states), so confirm the requirements for your updated role in your state.

What if I'm a tenant and a subcontractor hired lower-tier subs I wasn't told about? How do I protect myself?

As a tenant, your main concern is lien exposure if lower-tier contractors or suppliers weren't paid and file liens against the property. In many states, anyone who contributes to the project—even tiers you didn't directly hire—may still have the right to lien the property.

To protect yourself: 

• Confirm who has worked on the project and verify that everyone has been paid before releasing final payments. 
• Collect lien waivers from all tiers before making final disbursements. 
• Review your lease to understand whether you (as the tenant) bear any responsibility for clearing liens on the landlord's property. 

And if someone files or threatens a lien, speak with a construction attorney in your state as these situations are highly fact-specific.

Staying Protected

What's the most common reason for losing construction lien rights?

The number-one most common reason is missing a deadline, usually for a preliminary notice or the lien filing itself. These deadlines are unforgiving: in most states, missing them means your rights are gone, full stop.

The second most common issue is execution errors: incorrect forms, incomplete information, wrong property description, or failing to serve notice of the filed lien on the correct parties within the required window.

The safest approach is to treat lien rights as a system, not an afterthought. Know your deadlines before you start work, send preliminary notices early, and track everything centrally across all your projects.

How can Siteline help with lien rights management?

Siteline has built state-specific lien requirements directly into the software, so you can see exactly what steps are required to protect your rights on each project, in every state. The lien rights tracker shows you which jobs are protected, which are at risk, and what actions are needed, along with automated reminders so nothing slips through the cracks. 

You can generate and send preliminary notices and notices of intent directly from the platform, too, including via certified mail.

Want to see it in action? Schedule a demo, and we'll walk you through how it fits into your billing workflow.